Three-time champion Nikolay Davydenko crashed out in the first round of the Kremlin Cup in Moscow as he was defeated by Russian compatriot Alex Bogomolov.

Davydenko, a former world number three but now down at 40th in the rankings, won the title in his home city in 2004, 2006 and 2007 but went down 7-5 6-4 to Bogomolov.

The 29-year-old, who reached the quarter-finals of the event last year, expressed his delight after getting the better of Davydenko in straight sets.

"It was emotionally tough on both of us, especially playing in our homeland," Bogomolov told the ATP Tour's website.

"I was very aggressive to end the first set and then went up 4-0 in the second set. Again, Nikolay displayed some great tennis from the back of the court and was able to climb back to 4-4. I kept my composure and I think that was the main reason I was able to pull it out."

Argentinian seventh seed Carlos Berlocq ended the hopes of another Russian, Andrey Kuznetsov, as he overcame a sluggish start to record a 1-6 6-4 6-3 triumph.

Elsewhere, there were also wins for Holland's Igor Sijsling and home qualifier Konstantin Kravchuk.